Search

Recently, synonymizing Eisenia with Ecklonia was suggested based on a molecular phylogeny using the rbcL gene and ITS1–5.8S rDNA sequences. However, in a multigene molecular phylogeny based on mitochondrial cox1, cox3 genes and the atp8–16S rDNA region, as well as the plastid atpB, psaA, psbA and rbcL genes, Ecklonia spp. formed a monophyletic clade supported by high statistical values, and Eisenia spp. showed monophyly depending on analytical methods. The Japanese Eisenia species that used to be identified as Eisenia arborea (E. arborea sensu Arasaki) was shown to be genetically distant from E. arborea from the NE Pacific and E. bicyclis from Japan. Eisenia spp. were morphologically distinct in having a split meristematic zone in the mature thallus forming a dorsi-ventral blade with false branches. Therefore, we propose reinstatement of Eisenia as an independent genus and describe a new species, Eisenia nipponica (= E. arborea sensu Arasaki) from Japan. E. nipponica is distributed on the Pacific Coast of central Honshu, having a separate geographic range from E. bicyclis, which is distributed on the Pacific coast of eastern Honshu and the Sea of Japan coast of north-western Honshu and northern Kyushu. [ABSTRACT FROM AUTHOR]

SUMMARY: Reinstatement of Myelophycus caespitosus Kjellman (Ectocarpales s.l., Phaeophyceae) described from western Japan is proposed based on the comparisons of DNA sequences of Japanese Myelophycus specimens, the type specimen of Chordaria simplex and lectotypified specimen of Myelophycus caespitosus. In the genetic analyses using mitochondrial cox1 and cox3, chloroplast atpB, psbA and rbcL DNA sequences, the specimens morphologically referable to M. simplex formed two distinct clades (clade‐1 and clade‐2) supported by high statistical values. Clade‐1 was distributed on the western coast of Japan (Honshu, Shikoku and Kyushu) from the Kii Peninsula to Tsushima and the Pacific coast of Aomori, northeastern Honshu, and clade‐2 on the Pacific coast of central Honshu from Sanriku to the Kii Peninsula. Based on the cox3 DNA sequences and the location of the type locality at Shimoda, Izu Peninsula, clade‐2 was concluded to correspond to true M. simplex. There were no recognizable differences in the representative morphological features (height and diameter of sporophytes and gametophytes, number of cells comprising cortical, subcortical and medullary layers, thickness of plurilocular gametangia, or length and diameter of unilocular zoidangia) between the specimens included in the two taxa. Analyses of the specimens of the two taxa, including sympatric populations on the Kii Peninsula, using a nuclear genetic marker ocm3 did not suggest any genetic exchanges between the two taxa. On the other hand, cox3 gene sequence of the voucher specimen of Myelophycus caespitosus collected from Goto, Kyushu, western Japan housed in the UPS herbarium was included in clade‐1. In conclusion, we propose the reinstatement of M. caespitosus and to lectotypify the specimen in UPS. Korean Myelophycus specimens reported from Cheju Island and Wando were considered to belong to M. caespitosus based on the reported rbcL sequences. [ABSTRACT FROM AUTHOR]

Molecular phylogeny of Eudesme specimens collected from various localities in the Northern Hemisphere using mitochondrial cox1 and cox3 and chloroplast atpB, psaA, psbA and rbcL gene sequences revealed an undescribed species in the genus. In the analyses, three distinct clades (clades 1, 2 and 3) with high statistical supports were recognised. Specimens of clade 1 corresponded to the generitype E. virescens because the morphology agreed with the reported descriptions of the species, and the distribution (subboreal Europe) included the type locality. Clade 2 had a broad distribution in the Arctic Sea and coldwater regions of the northern Pacific and northern Atlantic. Specimens of clade 2 were morphologically distinguishable from E. virescens in having broader sporophytes. Specimens of clade 3 collected from western Honshu, Japan, had cox3 sequence identical to one of an old voucher specimen of E. shandongensis (63-519) described from the Yellow Sea. We propose the establishment of a new species, E. borealis, distributed in the Arctic, northern Pacific, and northern Atlantic regions. [ABSTRACT FROM AUTHOR]